Abstract: A semiconductor laser device having an active layer, a pair of cladding layers interposing the active layer and a multi-quantum barrier provided between one of the pair of cladding layers and the active layer is provided, and the multi-quantum barrier includes barrier layers and well layers being alternated with each other. The semiconductor laser device also including an optical guide layer confining light generated in a quantum well layer, and the optical guide layer being undoped.

Abstract: Excimers are generated by directing an electron beam at about 5 KeV to about 40 KeV into an excimer forming gas such as He, Ne, Ar, Kr, and Xe or mixtures of these with other gases through a ceramic foil such as SiN.sub.x. Vacuum ultraviolet (VUV) light is emitted by the excimers or by other species in contact therewith. The invention can provide intense, continuously operable broadband or monochromatic VUV light sources.

Abstract: The present invention provides a high density, edge emitting laser array structure formed by a wet oxidation process. Native oxide layers formed in adjacent grooves in the p-cladding layer Al-based alloy of the laser array structure provide both optical confinement to achieve single transverse mode operation and for electrical isolation to allow each laser diode to be independently addressable.

Abstract: A device and method for fabricating a high power laser diode device with an output emission with a nearly circular mode profile for efficient coupling into an optical fiber. A vertical taper waveguide and a window tolerance region are formed in a base structure of the device employing successive etching steps. Further regowth completes the device structure. The resultant laser device has a vertical and lateral tapered waveguide that adiabatically transforms the highly elliptical mode profile in an active gain section of the device into a substantially circular mode profile in a passive waveguide section of the device.

Abstract: An external cavity, continuously tunable wavelength source comprising a coherent light source having an external cavity including a reflector, such as a mirror or right-angle prism, for reflecting a selected wavelength from a diffraction grating back into the coherent light source. The wavelength is selected by simultaneous rotation and linear translation of the reflector about a pivot point such that the optical path length of the external cavity is substantially identical to a numerical integer of half wavelengths at a plurality of tunable wavelengths about a central wavelength of a tunable bandwidth for the source such that cavity phase error is zero at the central wavelength and is maximally flat on either side of the center wavelength within the tunable bandwidth. The location of said pivot axis is chosen to set the cavity phase error equal to zero and its first and second derivatives substantially equal to zero at exactly one wavelength.

Abstract: A microlaser cavity is provided with a solid active medium (2), an entry mirror (4), an exit mirror (60) and a layer of electrically resistive material formed on one of the surfaces of the microcavity. The electrically resistive layer has optical transparency and reflectivity properties adapted to the surface of the microcavity on which the layer is deposited.

Abstract: An optical semiconductor device circuit including a MI-DFB-LD capable of minimizing an extension in the wavelength of the output light in order to improve transmission speed and distance. The optical device circuit includes a semiconductor laser diode; an optical modulator for modulating output light of the semiconductor laser diode; a resistive element which is connected to the laser diode and which operates as a resistor at a high frequency; common connection substrate connected to the semiconductor laser diode and to the optical modulator; impedance element or signal reflection element connected to the common connection substrate; and ground connected to the impedance element or the signal reflection element.

Abstract: A laser diode 11 performs switching operation with a high speed in response to a digital-modulated electric signal inputted in differential input terminals 10a and 10b. At this time, a voltage detecting portion 14 detects a terminal voltage of the laser diode 11. A peak detecting portion 15 detects a peak value of output of the voltage detecting portion 14. A current control portion 16 controls a drive current of the laser diode 11 in accordance with an output of the peak detecting portion 15. The current control portion 16 includes a reference voltage generating portion 16a generating a reference voltage, and an error detecting portion 16b detecting an error between the reference voltage generated by the reference voltage generating portion 16a and the output of the peak detecting portion 15. In accordance with an output signal of the error detecting portion 16b, the drive current of the laser diode 11 is controlled.

Abstract: A semiconductor laser device having a multiplicity of individual lasers disposed in a laser-active region within outer boundary surfaces having front and rear boundary surfaces extending crosswise to an exit direction of the laser light, and lateral, bottom and top boundary surfaces extending parallel to the exit direction of the laser light, includes an absorption layer for decoupling photons interfering with desired laser operation, the absorption layer being applied full-surface to all of the outer boundary surfaces of the laser device, except for the laser-active region for at least one of the front and the rear boundary surfaces, respectively, extending crosswise to the exit direction of the laser light, and except for a relatively few locations remaining free for disposing terminal electrodes thereon or for introducing pump light thereat.

Abstract: A semiconductor laser device comprises an n-type cladding layer, an active layer formed on the n-type cladding layer and having a quantum well structure including one or a plurality of quantum well layers, a p-type cladding layer comprising a flat portion formed on the active layer and a stripe-shaped ridge portion on the flat portion, and a current blocking layer formed on the flat portion so as to cover the side surface of the ridge portion and formed on a region on the upper surface of the ridge portion from one of facets of a cavity to a position at a predetermined distance therefrom.

Abstract: A system and method for operating a high power laser diode device with high efficiency coupling of a laser diode bar. The laser diode bar and a micro-cylinder lens are vertically oriented in a device package, such that the array axis of the laser bar and the longitudinal axis of the micro-cylinder lens are aligned substantially parallel to a gravity vector. In the two different embodiments disclosed, either initial collimation of the fast-axis divergence or, alternatively, initial collimation of both the fast-axis and slow-axis divergences take place before beam reformatting via a beam array turning mirror. Additionally, the vertical orientation of these components is combined with methods of compensating for the bending or "smile" of the laser diode bar to provide for optimal output beam coupling, resulting in a uniform far field intensity distribution.

Abstract: Apparatus for stabilizing multiple laser sources having distinguishable optical characteristics, e.g., in polarization field or operational wavelength, comprises a plurality of semiconductor laser sources having respective lasing cavities capable of lasing within a narrow bandwidth of wavelengths and providing spectral outputs at their respective laser exit facets having different optical characteristics from one another. The spectral output beams of the sources may be coupled to respective optical fibers and the beams combined via a beam combiner, e.g., a polarizing beam combiner or a WDM combiner. The beam combiner combines the beam outputs forming a single beam which is launched into an output optical fiber. At least one feedback fiber grating is provided in at least one of the optical fibers with the number thereof depending upon distinguishable optical characteristics of the multiple laser sources.

Abstract: The crystal isolation system of the present invention protects a laser crystal from environmental factors such as humidity and dust. A crystal is placed in a housing which has two ports in it, and flexible tubes are placed in each port. Cap pieces cover the ends of the tubes and prevent deleterious environmental factors such as dust and moisture from entering the isolation system while allowing laser light to enter the system. A desiccator attached to the system removes moisture from the air inside the system, and an led and detector apparatus are is used to help indicate the remaining useful life of the desiccant in the desiccator.

Abstract: A surface laser diode package having an optical power monitoring function for a surface laser beam has a surface laser diode for making a spontaneous emission beam generated from an active region oscillate by means of an upper mirror and a lower mirror, and emitting a surface laser beam obtained by the oscillation. A monitor diode, installed between a substrate and the lower mirror of the surface laser diode, performs a light detection operation with respect to the surface laser beam emitted toward the substrate via the lower mirror, in order to monitor the optical power of the surface laser diode.

Abstract: A burying-heterostructure (BH) type semiconductor laser having a constricted mesa which has an active region. The laser has two spaces, located above and below the active region, for constricting a current to reduce a leakage current. The laser further has a first group of columns extending through the space located above the active region, and a second group of columns extending through the space located below the space. The columns of the first group are staggered in a vertical plane, with respect to the columns of the second group.

Abstract: In an optical device having a diffraction grating and at least two surfaces for reflecting light, the oscillation state is switched between a first oscillation state mainly based on resonance by distributed reflection by the diffraction grating, and a second oscillation state mainly based on Fabry-Perot resonance between the two surfaces. The characteristics of one of two modes to be used are improved at the cost of coherence of the other mode.

Abstract: In accordance with the present invention, a wavelength selectable laser source comprises a tunable pump source, an array of waveguide lasers for emitting light at respectively different wavelengths and a router for directing light from the pump source to an appropriate waveguide laser. A second router can be used to direct all laser outputs to a common output waveguide. The result is a wavelength selectable, stable signal source. In preferred embodiments the routers are dense wavelength-division multiplexers (DWDMs) and the waveguide lasers are rare-earth doped fiber lasers. Alternative embodiments provide a variety of ways of routing the pumping source.

Abstract: The lateral confinement region provided on both sides of an active region stripe of a buried heterostructure laser is formed of an alloy of InGaAsP instead of the conventional Fe doped InP material. This results in much improved regrowth morphology while still achieving good current and light blocking properties.

Abstract: In accordance with the first present invention, a cladding layer is provided between a gallium nitride based semiconductor active region and a substrate made of a material having a refraction index which is not lager than a refraction index of gallium nitride. The cladding layer includes at least one Al.sub.x Ga.sub.1-x N layer. An averaged value of the index "x" of aluminum of the above at least one Al.sub.x Ga.sub.1-x N layer is in the range of not less than 0.01 to less than 0.05 and a total thickness of the above at least one Al.sub.x Ga.sub.1-x N layer is not less than 0.7 micrometers as well as the cladding layer has an averaged refractive index which is lower than the refractive index of gallium nitride.

Abstract: A microchip laser is formed from at least one portion of laser material and at least one nonlinear crystal. The laser material and nonlinear crystal are in physical contact with each other and an angled surface of either the laser material or the nonlinear crystal forms an air-spaced etalon between the laser material and the nonlinear crystal. The axis of the microchip laser passes through the etalon formed between the laser material and the nonlinear crystal. The etalon in the laser cavity produces a single mode output. Additionally, the nonlinear crystal within the cavity may operate, in conjunction with a polarization dependent gain cross-section in the laser material, as a birefringent filter to reduce the bandwidth of laser emission from a broadband active laser material.